544 research outputs found
Potential of Lactobacillus casei , Culture Permeate, and Lacti Acid To Control Microorganisms in Ready-To-Use Vegetables.
The effects of various treatments (i.e., the addition of a strain of Lactobacillus that produces antimicrobial agents, Lactobacillus casei IMPC LC34, its sterile permeate, and 0.5 or 1% lactic acid) on the growth of microorganisms associated with ready-to-use mixed salad vegetables were compared during refrigerated (8°C) storage. The addition of 3% culture permeate to mixed salads reduced the total mesophilic bacteria counts from 6 to 1 log CFU/g, and suppressed coliforms, enterococci, and Aeromonas hydrophila after 6 days of storage at 8°C. A similar effect was shown when the L. casei culture was inoculated in the vegetables. One percent lactic acid had a bacteriostatic effect on the bacterial groups examined, except for total and fecal coliforms, which were reduced by about 2 and 1 log unit, respectively, while 0.5% lactic acid did not affect the indigenous microflora of the vegetables. The potential of these new hurdles to prevent the growth of spoilage and pathogenic bacteria in ready-to-use salad vegetables is suggested
Wave reflection at a free interface in an anisotropic pyroelectric medium with nonclassical thermoelasticity
In this paper, the well-established two-dimensional mathematical model for linear pyroelectric materials is employed to investigate the reflection of waves at the boundary between a vacuum and an elastic, transversely isotropic, pyroelectric material. A comparative study between the solutions of (a) classical thermoelasticity, (b) Cattaneo–Lord–Shulman theory and (c) Green–Lindsay theory equations, characterised by none, one and two relaxation times, respectively, is presented. Suitable boundary conditions are considered in order to determine the reflection coefficients when incident elasto–electro–thermal waves impinge the free interface. It is established that, in the quasi-electrostatic approximation, three different classes of waves: (1) two principally elastic waves, namely a quasi-longitudinal Primary (qP) wave and a quasi-transverse Secondary (qS) wave; and (2) a mainly thermal (qT) wave. The observed electrical effects are, on the other hand, a direct consequence of mechanical and thermal phenomena due to pyroelectric coupling. The computed reflection coefficients of plane qP waves are found to depend upon the angle of incidence, the elastic, electric and thermal parameters of the medium, as well as the thermal relaxation times. The special cases of normal and grazing incidence are also derived and discussed. Finally, the reflection coefficients are computed for cadmium selenide observing the influence of (1) the anisotropy of the material, (2) the electrical potential and (3) temperature variations and (4) the thermal relaxation times on the reflection coefficients
Electronic structure and magnetic properties of epitaxial FeRh(001) ultra-thin films on W(100)
Epitaxial FeRh(100) films (CsCl structure, thick), prepared
{\it in-situ} on a W(100) single crystal substrate, have been investigated via
valence band and core level photoemission. The presence of the
temperature-induced, first-order, antiferromagnetic to ferromagnetic
(AF FM) transition in these films has been verified via linear
dichroism in photoemission from the Fe 3 levels. Core level spectra indicate
a large moment on the Fe atom, practically unchanged in the FM and AF phases.
Judging from the valence band spectra, the metamagnetic transition takes place
without substantial modification of the electronic structure. In the FM phase,
the spin-resolved spectra compare satisfactorily to the calculated
spin-polarized bulk band structure.Comment: 7 pages, 5 figure
Extraction and Partial Characterization of Proteolytic Activities from the Cell Surface of Lactobacillus helveticus Zuc2
Abstract Proteolytic activities were extracted from a dairy Lactobacillus helveticus strain and partially characterized. A first cell envelope proteinase (CEP) was extracted using a high ionic strength buffer, both in the presence and in the absence of Ca 2+ . Moreover, cell treatment by 5 M LiCl allowed for the selective removal of the S-layer protein and CEP, suggesting an enzyme ionic linkage to the cell envelope similar to that observed for the Slayer structure. The enzyme specificity against α s1 -CN (f1–23) showed unusual activity on the Lys 3 -His 4 bond compared with other proteinases of the same species. A second proteinase appeared to be linked to the cell membrane because it was extractable only after membrane disgregation by detergents. Its specificity against CN fractions and α s1 -CN (f1–23) was different from that of the first CEP; moreover, the measured activity was lower than that of CEP
Glutamate induces autophagy via the two-pore channels in neural cells
NAADP (nicotinic acid adenine dinucleotide phosphate) has been proposed as a second messenger for glutamate in neuronal and glial cells via the activation of the lysosomal Ca2+ channels TPC1 and TPC2. However, the activities of glutamate that are mediated by NAADP remain unclear. In this study, we evaluated the effect of glutamate on autophagy in astrocytes at physiological, non-toxic concentration. We found that glutamate induces autophagy at similar extent as NAADP. By contrast, the NAADP antagonist NED-19 or SiRNA-mediated inhibition of TPC1/2 decreases autophagy induced by glutamate, confirming a role for NAADP in this pathway. The involvement of TPC1/2 in glutamate-induced autophagy was also confirmed in SHSY5Y neuroblastoma cells. Finally, we show that glutamate leads to a NAADP-dependent activation of AMPK, which is required for autophagy induction, while mTOR activity is not affected by this treatment. Taken together, our results indicate that glutamate stimulates autophagy via NAADP/TPC/AMPK axis, providing new insights of how Ca2+ signalling glutamate-mediated can control the cell metabolism in the central nervous system
Design and Field Measurements of a Linear Accelerator Endowed with Single Feed with Movable Short Coupler
Field asymmetries in the rf coupler of accelerating structures degrade the projected beam transverse emittance, especially at low energy. This paper presents an alternative single feed coupler design that reduces the dipolar
and the quadrupolar field components by exploiting a movable short circuit placed on the opposite waveguide. The structure has been simulated and optimized with the Ansys HFSS simulation code. RF measurements on an aluminum prototype machined in the "Elettra - Sincrotrone Trieste S.C.p.A.", are here presented. Such results are in good agreement with the simulations
Adult patients with grown-up congenital heart disease: Lights and shadows
GUCH is acronym of grown-up congenital heart of patients who become adults after cardiac surgery. The history of this population is in progress (temporal perspective), and long-term post-surgical follow-up revealed the paradoxical meaning of correction of complex congenital heart disease, because surgery does not restore normality: It prolongs life, improves symptoms, functional capacity, but it is often associated with illness and peculiar needs. Not only survival but also health-related quality of life, which is strictly connected to clinical status, socio-economic situation, psychological conditions, cognitive functions, level of care with particular attention to gender differences. Currently the history of these patients is better known: A multidisciplinary team of cardiologists with specific training in congenital heart disease, psychologists, neurophysiologists, obstetricians, social workers, experts in human science can improve the possibilities of these patients to realize their effective and safe project of life
Weakly Coupled Motion of Individual Layers in Ferromagnetic Resonance
We demonstrate a layer- and time-resolved measurement of ferromagnetic
resonance (FMR) in a Ni81Fe19 / Cu / Co93Zr7 trilayer structure. Time-resolved
x-ray magnetic circular dichroism has been developed in transmission, with
resonant field excitation at a FMR frequency of 2.3 GHz. Small-angle (to 0.2
degree), time-domain magnetization precession could be observed directly, and
resolved to individual layers through elemental contrast at Ni, Fe, and Co
edges. The phase sensitivity allowed direct measurement of relative phase lags
in the precession oscillations of individual elements and layers. A weak
ferromagnetic coupling, difficult to ascertain in conventional FMR
measurements, is revealed in the phase and amplitude response of individual
layers across resonance.Comment: 22 pages, 6 figures submitted to Physical Review
Testo con figura
The Engramma issue “Text and Image” is a collection of case studies where a clear, univocal relationship between a text and an image emerges in a complex relation. Images here are not mere illustrations – just as texts are not mere captions. In this framework, we publish the following contributions: Piermario Vescovo, "Tre astrologi e la luna"; Francesca Bortolanza, "Un nuovo documento su Altadona, madre di Giorgione"; Monica Centanni, "Figura con testo. Nota su una assonanza tra il Capitolo dell’Ingratitudine di Machiavelli e la Calunnia di Botticelli"; Chiara Italiano, "Un dragonesco Giorgio nella cattedrale della Recherche. San Giorgio di Mantegna nel Cahier 46 di Sodome et Gomorrhe"; Davide Susanetti, "Jung, Polifilo e la Ninfa"; Nicola Giaccone, "Ade e Barbablù. Una genealogia?"; Orazio Licandro, "Dictator o tyrannus? Propaganda in figura, in un denario di Bruto"; Silvia Ronchey, "Caterina / Ipazia. La Santa fantasma", and Francesco Monticini, "Παῖδας ἐγὼ λόγους ἐγεννησάμην. Libri come figli. Fra testo e figura: Teodoro Metochita e Sinesio di Cirene". We also publish three reviews: Maria Grazia Ciani reviews Lorenzo Braccesi’s "Un poeta per Cassandra", Filippo Perfetti presents Giovanni Careri’s "Ebrei e cristiani nella Cappella Sistina", and Daniela Sacco presents James Hillman, Silvia Ronchey, "L’ultima immagine", Rizzoli Milano 2021
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